Lincoln Electric IM10015 TOMAHAWK 375 AIR - Manual (Page 17)

PROCEDURE RECOMMENDATIONS
When properly used, plasma arc cutting is a very eco-
nomical process. Improper use will result in a very
high operating cost.
General - In All Cases
• Follow safety precautions as printed throughout this
operating manual and on the machine.
• If piercing is required, slowly lower the torch at an
angle of about 30° to blow the dross away from
the torch tip and slowly rotate the torch to a ver-
tical position as the arc becomes deeper. This
process will blow a lot of molten metal and
dross. Be careful! Blow the dross away from
the torch, the operator and any flammable
objects.
• The nozzle should not be dragged on the metal
surface. A drag spacer is provided to maintain a
consistant touch height. Refer to Touch Parts
Configurations in this Section.
• Where possible, start the cut from the edge of the
work piece.
• Keep moving! A steady speed is necessary. Do not
pause.
Torch Standoff
DRAG thru 1/16"
Standoff
1/16” Standoff
B-7 OPERATION B-7
TORCH
• During operation, if the Red and Yellow LEDʼs light
together:
• Check the assembly of the torch consumables. If
they are not properly in place, the machine will not
start. Make sure that the shield cup is hand
tight. Do not use pliers or over tighten.
• Check the conditions of the inside of the nozzle. If
debris has collected, rub the electrode on the inside
bottom of the nozzle to remove any oxide layer that
may have built up. Refer to "Suggestions for Extra
Utility from the TOMAHAWK™ 375 AIR system".
• Check the condition of the electrode. If the end has
a crater-like appearance, replace it along with the
nozzle. The maximum wear depth of the electrode
is approximately .062”. A green and erratic arc will
indicate definite electrode failure and the electrode
should be replaced immediately.
• Replace the nozzle when the orifice exit is eroded
away or oval shaped.
• After the problem is found, or if there is nothing
apparently wrong, reset the machine by turning the
power switch OFF and then ON again. (It is possi-
ble for electrical noise to trip the safety circuit on
rare occasions. This should not be a regular occur-
rence.)
• If the machine does not reset or continues to trip,
consult the Troubleshooting Section.
• Use the proper cutting procedures referred to in
Procedure Recommendations.
PILOT ARC DISCUSSION
The TOMAHAWK™ 375 AIR has a smooth, continu-
ous pilot arc. The pilot arc is only a means of transfer-
ring the arc to the workpiece for cutting. Repeated
pilot arc starts, in rapid succession, is not recom-
mended as these starts will generally reduce consum-
able life. Occasionally, the pilot arc may sputter or
start intermittently. This is aggravated when the con-
sumables are worn or the air pressure is too high.
Always keep in mind that the pilot arc is designed to
transfer the arc to the workpiece and not for numerous
starts without cutting.
The TOMAHAWK™ 375 AIR does not utilize high fre-
quency starting. When the pilot arc is started, a slight
impulse will be felt in the torch handle. This occur-
rence is normal and is the mechanism which starts the
plasma arc. This impulse can also be used to help
troubleshoot a "no start" condition.
TOMAHAWK™ 375 AIR